Locking arm system for a retention ramp of a lift gate

ABSTRACT

A locking assembly for a ramp of a lift gate, the locking assembly including: an elongated adjustable locking arm pivotably disposed on a pivot point relative to the ramp, the locking arm including an adjustment mechanism for adjusting a length of the locking arm disposed on a proximal end for engaging a cam portion, where the length of the locking arm can be increased or decreased by adjusting the adjustment mechanism; and a resilient member for spring loading the locking arm, where a biasing tension in the resilient member urges the proximal end of the locking arm to pivotably engage with the cam portion to maintain the ramp in a selected position; and at least one fastener for coupling the locking assembly to a first surface of the ramp.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 15/097,132 filed Apr. 12, 2016, which is a continuation of U.S.patent application Ser. No. 13/689,582 filed Nov. 29, 2012, which issuedas U.S. Pat. No. 9,341,212 on May 17, 2016, which claims the priority toand the benefit of U.S. Provisional Patent Application Ser. No.61/565,454, filed Nov. 30, 2011, all of which are incorporated herein byreference in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates generally to lift gates, and inparticular, to retention assemblies for ramps of lift gates.

Description of Related Art

Lifts such as lift gates are typically mounted at a structure such as anopening at the rear of a vehicle to lift payloads on a lift platformfrom one level (e.g., ground level) up to another level (e.g., the bedof the vehicle), or vice versa.

One type of lift gate employs a parallel pair of vertically extendingstandards, posts or columns, each having a vertically disposed actuatorfor vertically raising and lowering a lift platform between ground leveland the level of the bed of the vehicle. A collapsible linkage systeminterconnects the lift platform with the columns. The linkage systemmaintains the lift platform in a horizontal plane through the liftingrange.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a locking assembly for a retention rampsection of a lift gate. The locking assembly comprises an elongatedlocking arm and a spring for spring loading the locking arm. The lockingarm is pivotably disposed on a pivot point relative to the ramp. Abiasing tension in the spring urges a proximal end of the locking arm toengage with a cam portion of the ramp to maintain the ramp in a selectedposition. The cam portion has multiple engagement surfaces forindividually engaging with the locking arm, wherein selectively engagingthe locking arm with each engagement surface of the cam portionmaintains the ramp in a corresponding selected position.

In a locking assembly embodiment for a ramp of a lift gate, the lockingassembly may include: an elongated adjustable locking arm, where thelocking arm may be pivotably disposed on a pivot point relative to theramp, the locking arm may include an adjustment mechanism for adjustinga length of the locking arm disposed on a proximal end of the lockingarm for engaging a cam portion, where the length of the locking arm maybe increased or decreased by adjusting the adjustment mechanism at theproximal end of the locking arm; and a resilient member for springloading the locking arm, where a biasing tension in the resilient memberurges the proximal end of the locking arm to pivotably engage with thecam portion to maintain the ramp in a selected position; and at leastone fastener for coupling the locking assembly to a first surface of theramp, where the first surface of the ramp may be disposed opposite froma second surface of the ramp, and where the second surface of the rampmay be unobstructed in a ramp position of the selected position.

In additional embodiments of the locking assembly, the cam portion mayhave multiple engagement surfaces for individually engaging with thelocking arm, such that selective engagement of the locking arm with eachengagement surface of the cam portion maintains the ramp in the selectedposition. In additional embodiments of the locking assembly, the firstsurface of the ramp may be disposed distal from a lift platform sectionin a stowed position of the selected position. Additional embodiments ofthe locking assembly may include: a coupling member for rotatablycoupling the ramp to the lift platform section of the lift gate, thecoupling member including a channel in which the locking arm ispivotably disposed on a pivot axle along the length of the locking arm,such that the locking arm can pivot about the pivot axle for selectivelyengaging the cam portion. Additional embodiments of the locking assemblymay include: the locking arm pivotably disposed on said pivot axle alongthe length of the locking arm between the proximal end of the lockingarm and a distal end of the locking arm; and upon exerting a force onthe distal end of the locking arm to overcome the tension in the spring,the locking arm pivots to disengage the proximal end of the locking armfrom the cam portion and allows the ramp to be rotated relative to thelift platform section.

In additional embodiments of the locking assembly, when the proximal endof the locking arm engages with a first engagement surface of the camportion, the ramp may be maintained in the stowed position by thelocking arm, such that the ramp is folded against a section of the liftplatform section, when the proximal end of the locking arm engages witha second engagement surface of the cam portion, the ramp may bemaintained in a retention position by the locking arm, such that theramp is substantially transverse to the lift platform section, and/orwhen the proximal end of the locking arm engages with a third engagementsurface of the cam portion, the ramp may be maintained in a rampposition, such that the ramp is substantially aligned with the liftplatform section.

In additional embodiments of the locking assembly, upon exerting a forceon the distal end of the locking arm to overcome the tension in thespring, the locking arm may pivot to disengage the proximal end of thelocking arm from the cam portion and allow the ramp to be rotatedrelative to the lift platform section between the stowed position, aretention position, the ramp position. In additional embodiments of thelocking assembly, the distal end of the locking arm may rotate into thechannel as the proximal end of the locking arm rotates away to disengagethe cam portion due to exertion of the force on the distal end of thelocking arm; and upon removing the force on the distal end of thelocking arm, the resilient member pivots the locking arm to rotate theproximal end into engagement with the cam portion and maintain the rampin the selected position relative to the lift platform section. Inadditional embodiments of the locking assembly, a bottom of the channelmay limit the rotational range of the distal end of the locking arm.

In additional embodiments of the locking assembly, the adjustmentmechanism may further include an adjustable screw threadably disposed onthe proximal end of the locking arm for engaging the cam portion, wherepartially unscrewing or partially screwing the adjustable screw relativeto the proximal end of the locking arm may increase or decrease thelength of the locking arm. In additional embodiments of the lockingassembly, the adjustment mechanism may be disposed on the proximal endof the locking arm, such that the adjustment mechanism may allowselective adjustment of the length of a portion of the locking armbetween the pivot point and the cam portion. In additional embodimentsof the locking assembly, the adjustment mechanism may allow adjustingthe length of the locking arm to reduce a gap between the proximal endof the locking arm and an engagement surface of the cam portion. Inadditional embodiments of the locking assembly, when the proximal end ofthe locking arm engages with a first engagement surface of the camportion, the ramp may be maintained in a stowed position by the lockingarm, such that the ramp is folded against a section of the a liftplatform section; and the adjustment mechanism may allow adjusting thelength of the locking arm for engaging the cam portion to maintain theramp fully folded against the lift platform section in a stowed positionof the ramp.

A lift gate system may include: a lift platform section; a ramp, wherethe ramp may be rotatably coupled to the lift platform section; and alocking assembly for maintaining the ramp in a selected positionrelative to the lift platform section, where the locking assembly mayinclude: an elongated adjustable locking arm, where the locking arm maybe pivotably disposed on a pivot point relative to the ramp, where thelocking arm may include an adjustment mechanism for adjusting a lengthof the locking arm disposed on a proximal end of the locking arm forengaging a cam portion, where the length of the locking arm may beincreased or decreased by adjusting the adjustment mechanism at theproximal end of the locking arm; and a resilient member for springloading the locking arm, where a biasing tension in the spring urges theproximal end of the locking arm to pivotably engage with the cam portionto maintain the ramp in a selected position; at least one fastener forcoupling the locking assembly to a first surface of the ramp, where thefirst surface of the ramp may be disposed opposite from a second surfaceof the ramp, and where the second surface of the ramp may beunobstructed in a ramp position of the selected position.

In additional lift gate system embodiments, the cam portion may havemultiple engagement surfaces for individually engaging with the lockingarm, such that selective engagement of the locking arm with eachengagement surface of the cam portion maintains the ramp in the selectedposition. Additional lift gate system embodiments may include a liftingmechanism for supporting and moving the lift platform section.

In additional lift gate system embodiments, when the proximal end of thelocking arm engages with a first engagement surface of the cam portion,the ramp may be maintained in a stowed position by the locking arm, suchthat the ramp is folded against a section of the lift platform section;when the proximal end of the locking arm engages with a secondengagement surface of the cam portion, the ramp may be maintained in aretention position by the locking arm, such that the ramp issubstantially transverse to the lift platform section; and when theproximal end of the locking arm engages with a third engagement surfaceof the cam portion, the ramp may be maintained in a ramp position, suchthat the ramp is substantially aligned with the lift platform section.

A method embodiment may include: maintaining a ramp of a lift gate in aselected position by engaging an elongated adjustable locking arm with acam portion, the locking arm including an adjustment mechanism foradjusting a length of the locking arm disposed on a proximal end of thelocking arm for engaging a cam portion of the ramp; and increasing ordecreasing the length of the locking arm by adjusting the adjustmentmechanism at the proximal end of the locking arm; where the locking armmay be spring loaded by a resilient member having a biasing tension thaturges the proximal end of the locking arm to pivotably engage with thecam portion to maintain the ramp in a selected position; where the camportion may have multiple engagement surfaces for individually engagingwith the locking arm, such that selective engagement of the locking armwith each engagement surface of the cam portion maintains the ramp inthe selected position; and wherein the locking assembly may be coupledto a first surface of the ramp, where the first surface of the ramp maybe disposed opposite from a second surface of the ramp, and where thesecond surface of the ramp may be unobstructed in a ramp position of theselected position.

These and other features, aspects and advantages of the presentinvention will become understood with reference to the followingdescription, appended claims and accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of a lift gate system, inaccordance with an embodiment of the invention.

FIG. 2A illustrates the pivoting range of the ramp relative to theflipover, in accordance with an embodiment of the invention.

FIG. 2B illustrates the lift platform in the lowered position and theramp maintained in the stowed position, in accordance with an embodimentof the invention.

FIG. 2C illustrates the lift platform in the lowered position and theramp maintained in the retention position, in accordance with anembodiment of the invention.

FIG. 2D illustrates the lift platform in the lowered position and theramp maintained in the ramp position, in accordance with an embodimentof the invention.

FIG. 3 illustrates an example locking assembly, in accordance with anembodiment of the invention.

FIG. 4A illustrates a side perspective view of the lift platform in thestowed position, in accordance with an embodiment of the invention.

FIG. 4B illustrates a cross-sectional view of the lift gate in FIG. 4Aabout an axis A-A (FIG. 4A), in accordance with an embodiment of theinvention.

FIG. 5A illustrates a side perspective view of the lift gate in thestowed position after the lift gate has been used for a period of time,in accordance with an embodiment of the invention.

FIG. 5B illustrates a side view of the lift gate in FIG. 5A, inaccordance with an embodiment of the invention.

FIG. 5C illustrates a cross-sectional view of the lift gate in FIG. 5Aabout an axis A-A (FIG. 5A), in accordance with an embodiment of theinvention.

FIG. 6A illustrates an example locking assembly with an adjustablelocking arm, in accordance with an embodiment of the invention.

FIG. 6B illustrates an example locking assembly with an adjustablelocking arm, wherein the ramp is maintained in the stowed position, inaccordance with an embodiment of the invention.

FIG. 7A illustrates a top perspective view of the adjustable lockingarm, in accordance with an embodiment of the invention.

FIG. 7B illustrates a top view of the adjustable locking arm, inaccordance with an embodiment of the invention.

FIG. 7C illustrates a cross-sectional view of the adjustable lockingarm, in accordance with an embodiment of the invention.

FIG. 7D illustrates a back view of the adjustable locking arm, inaccordance with an embodiment of the invention.

FIG. 7E illustrates a side view of the adjustable locking arm, inaccordance with an embodiment of the invention.

FIG. 7F illustrates a front view of the adjustable locking arm, inaccordance with an embodiment of the invention.

FIG. 7G illustrates a front perspective view of the adjustable lockingarm, in accordance with an embodiment of the invention.

FIG. 7H illustrates a back perspective view of the adjustable lockingarm, in accordance with an embodiment of the invention.

FIG. 7I illustrates an exploded view of the adjustable locking arm, inaccordance with an embodiment of the invention.

FIG. 8A illustrates a top perspective view of the ramp when the ramp ismaintained in the stowed position, in accordance with an embodiment ofthe invention.

FIG. 8B illustrates a side view of the ramp when the ramp is maintainedin the stowed position, in accordance with an embodiment of theinvention.

FIG. 9 illustrates a top perspective view of the locking assembly whenthe ramp is released from the stowed position, in accordance with anembodiment of the invention.

FIG. 10 illustrates a side perspective view of the locking assembly whenthe ramp is moved to the retention position, in accordance with anembodiment of the invention.

FIG. 11A illustrates a side perspective view of the ramp when the rampis maintained in the retention position, in accordance with anembodiment of the invention.

FIG. 11B illustrates a side view of the ramp when the ramp is maintainedin the retention position, in accordance with an embodiment of theinvention.

FIG. 12 illustrates a side perspective view of the locking assembly whenthe ramp is released from the retention position, in accordance with anembodiment of the invention.

FIG. 13A illustrates a top perspective view of the ramp when the ramp ismaintained in the ramp position, in accordance with an embodiment of theinvention.

FIG. 13B illustrates a side view of the ramp when the ramp is maintainedin the ramp position, in accordance with an embodiment of the invention.

FIG. 14 illustrates a side view of the locking mechanism when the rampis maintained in the stowed position, in accordance with an embodimentof the invention.

FIG. 15 illustrates a top perspective view of an example lockingassembly and an example hinge assembly that pivotally couples the rampto the flipover, in accordance with an embodiment of the invention.

FIG. 16 illustrates a top perspective view of example locking assembliesthat pivotally couple the ramp to the flipover, in accordance with anembodiment of the invention.

FIG. 17A illustrates a perspective view of the ramp in a stowed positionrelative to the flipover, in accordance with an embodiment of theinvention.

FIG. 17B illustrates a perspective view of the ramp in a retentionposition relative to the flipover, in accordance with an embodiment ofthe invention.

FIG. 17C illustrates a perspective view of the ramp in a ramp positionrelative to the flipover, in accordance with an embodiment of theinvention.

FIG. 18A illustrates a perspective close-up view of the ramp in a lockedstowed position relative to the flipover, in accordance with anembodiment of the invention.

FIG. 18B illustrates a perspective close-up view of the ramp in anunlocked stowed position relative to the flipover, in accordance with anembodiment of the invention.

FIG. 18C illustrates a perspective close-up view of the ramp in a lockedretention position relative to the flipover, in accordance with anembodiment of the invention.

FIG. 18D illustrates a perspective close-up view of the ramp in anunlocked retention position relative to the flipover, in accordance withan embodiment of the invention.

FIG. 18E illustrates a perspective close-up view of the ramp in a rampposition relative to the flipover, in accordance with an embodiment ofthe invention.

FIGS. 19A-19E illustrate perspective, front, back, top, bottom, rightside, and left side views, respectively, of a locking arm bracket, inaccordance with an embodiment of the invention.

FIG. 20A illustrates a perspective view of the liftgate in a stowedposition, in accordance with an embodiment of the invention.

FIG. 20B illustrates a perspective view of the liftgate in a partiallyunstowed position, in accordance with an embodiment of the invention.

FIG. 20C illustrates a perspective view of the liftgate in an unstowedposition with the ramp in a stowed position relative to the flipover, inaccordance with an embodiment of the invention.

FIG. 20D illustrates a perspective view of the liftgate with the ramp ina retention position relative to the flipover, in accordance with anembodiment of the invention.

FIG. 20E illustrates a perspective view of the liftgate with the ramp ina ramp position relative to the flipover, in accordance with anembodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The following description is made for the purpose of illustrating thegeneral principles of the invention and is not meant to limit theinventive concepts claimed herein. Further, particular featuresdescribed herein can be used in combination with other describedfeatures in each of the various possible combinations and permutations.Unless otherwise specifically defined herein, all terms are to be giventheir broadest possible interpretation including meanings implied fromthe specification as well as meanings understood by those skilled in theart and/or as defined in dictionaries, treatises, etc.

The present invention relates to retention assemblies for ramps of liftgates. In one embodiment, the present invention provides a retentiondevice comprising a locking assembly for a ramp of a lift gate. Thelocking assembly comprises an elongated locking arm and a spring forspring loading the locking arm. The locking arm is pivotably disposed ona pivot point relative to the ramp. A biasing tension in the springurges a proximal end of the locking arm to engage with a cam portion ofthe ramp to maintain the ramp in a selected position. The cam portionhas multiple engagement surfaces for individually engaging with thelocking arm, wherein selectively engaging the locking arm with eachengagement surface of the cam portion maintains the ramp in acorresponding selected position. Upon exerting a force on the distal endof the locking arm to overcome the tension in the spring, the lockingarm pivots to disengage said proximal end of the locking arm from thecam portion and allows the ramp to be rotated relative to the liftplatform section.

In one embodiment, a coupling member rotatably couples the ramp to alift platform section of the lift gate. The coupling member includes achannel in which the locking arm is pivotably disposed on a pivot axlealong the length of the locking arm, such that the locking arm can pivotabout the pivot axle for selectively engaging the cam portion. In oneembodiment, the locking arm is pivotably disposed on said pivot axlealong the length of the locking arm between the proximal end and adistal end of the locking arm.

In one embodiment, the ramp is maintained in a stowed position byengaging the proximal end of the locking arm with a first engagementsurface of the cam portion, such that the ramp is folded against asection of the lift platform section. The ramp is maintained in aretention position by engaging the proximal end of the locking arm witha second engagement surface of the cam portion, such that the ramp issubstantially transverse to the lift platform section. The ramp ismaintained in a ramp position by engaging the proximal end of thelocking arm with a third engagement surface of the cam portion, suchthat the ramp is substantially aligned with the lift platform section.

Upon exerting a force on the distal end of the locking arm to overcomethe tension in the spring, the locking arm pivots to disengage saidproximal end of the locking arm from the cam portion and allows the rampto be rotated relative to the lift platform section between said stowedposition, retention position and ramp position. The distal end of thelocking arm rotates into said channel as the proximal end of the lockingarm rotates away to disengage the cam portion due to exertion of saidforce on the distal end of the locking arm. Upon removing said force onthe distal end of the locking arm, the spring pivots the locking arm torotate said proximal end into engagement with the cam portion andmaintain the ramp in a selected position relative to the lift platformsection. A bottom of the channel limits the rotational range of thedistal end of the locking arm.

In one embodiment, the locking arm further includes an adjustmentmechanism for adjusting the length of the locking arm. The adjustmentmechanism is disposed on said proximal end of the locking arm, such thatthe adjustment mechanism allows selective adjustment of the length of aportion of the locking arm between said pivot point and the cam portion.The adjustment mechanism allows adjusting the length of the locking armto reduce a gap between the proximal end of the locking arm and anengagement surface of the cam portion. When the proximal end of thelocking arm engages with a first engagement surface of the cam portion,the ramp is maintained in a stowed position by the locking arm, suchthat the ramp is folded against a section of the lift platform section.The adjustment mechanism allows adjusting the length of the locking armfor engaging the cam portion to maintain the ramp fully folded againstthe lift platform section in said stowed position of the ramp.

In one embodiment, the adjusting mechanism comprises an adjustable screwthreadably disposed on said proximal end of the locking arm for engagingthe cam portion. The length of the locking arm can be increased bypartially unscrewing the adjustable screw out of said proximal end ofthe locking arm. The length of the locking arm can be decreased bypartially screwing the adjustable screw into said proximal end of thelocking arm.

FIG. 1 illustrates a perspective view of a lift gate system (“liftgate”) 10, in accordance with an embodiment of the invention. The liftgate 10 is configured for mounting at a structure such as a rear frameof a vehicle (e.g., a truck). For example, the lift gate 10 may beattached to a rear frame 50A of a vehicle 70 as shown in FIG. 1.

The lift gate 10 comprises a lifting mechanism 52 including a parallelpair of vertically extending columns 51 for moving a lift platform 100between a raised position and a lowered position. Each column 51includes a vertically disposed actuator therein for vertically raisingand lowering the lift platform 100, such as between ground level 200(FIG. 2B) and the level of a vehicle bed 50 of the vehicle 70. A pair ofcollapsible linkages 53 interconnect the lift platform 100 with thecolumns 51 along linkage points on sides of the lift platform 100. Thelinkages 53 maintain the lift platform 100 in a horizontal plane throughthe lifting range. In one embodiment, the cam 6 is a portion of theramp. In another embodiment, the cam 6 is fixedly attached to the rampvia fastening devices such as screws or by welding.

The columns 51 raise/lower the lift platform 100 for lifting payloadsthereon from one level (e.g., ground level 200 in FIG. 2B) to anotherlevel (e.g., the vehicle bed 50 of the vehicle 70), or vice versa. InFIG. 1, the lift platform 100 is shown in an unfolded position, whereinthe lift platform 100 is substantially aligned with the vehicle bed 50when the lift platform 100 is in the raised position, as shown in FIG.1.

The lift platform 100 comprises at least one load-carrying surfaceincluding a platform section 1, a foldable section (“flipover”) 2, and aretention ramp section (“ramp”) 3.

The platform section 1 has a first edge 1A and a second edge 1B that isopposite of the first edge 1A. The flipover 2 has a first edge 2A and asecond edge 2B that is opposite of the first edge 2A. The first edge 2Aof the flipover 2 is pivotally coupled to the second edge 1B of theplatform section 1.

The ramp 3 has a first edge 3A and a second edge 3B that is opposite ofthe first edge 3A. The first edge 3A of the ramp 3 is pivotally coupledto the second edge 2B of the flipover 2 via at least one lockingassembly 30 (FIG. 3) or at least one locking assembly 31 (FIG. 6A). Inone embodiment, the first edge 3A of the ramp 3 is pivotally coupled tothe second edge 2B of the flipover 2 via a locking assembly 30 at oneside and a hinge assembly 40 at another side (FIG. 2B), wherein thelocking assembly 30 and the hinge assembly 40 are disposed at oppositeends (sides) 3E (FIGS. 15) and 3F (FIG. 15), respectively, of the firstedge 3A. In another embodiment, the first edge 3A of the ramp 3 ispivotally coupled to the second edge 2B of the flipover 2 via a lockingassembly 31 at one side and a hinge assembly 40 at another side (FIG.15), wherein the locking assembly 31 and the hinge assembly 40 aredisposed at opposite ends (sides) 3E (FIGS. 15) and 3F (FIG. 15),respectively, of the first edge 3A. In yet another embodiment, the firstedge 3A of the ramp 3 is pivotally coupled to the second edge 2B of theflipover 2 via a pair of locking assemblies 31 (FIG. 16), wherein eachlocking assembly 31 is disposed at an opposite end 3E (FIG. 16), 3F(FIG. 16) of the first edge 3A.

The ramp 3 is connected to a coupling member that comprises a hingemember 11 for rotatably coupling the ramp 3 to the flipover 2. Thecoupling member further includes a pivot member 12 (FIG. 3) such as anaxle pin for rotatably disposing the hinge member 11 relative to theflipover 2, thereby enabling the hinge member 12 (and the attached ramp3) to freely rotate relative to the flipover 2 when the locking assemblyis unlocked, as described herein.

FIG. 2A illustrates the pivoting range of the ramp 3 relative to theflipover 2, in accordance with an embodiment of the invention. The ramp3 pivots relative to the flipover 2. Each locking assembly 30, 31 thatpivotally couples the ramp 3 to the flipover 2 maintains (i.e., locks)the ramp 3 in a selected position. In one embodiment, the ramp 3 may bemaintained (i.e., locked) in a ramp position, a retention position, or astowed position.

As shown in FIG. 2A, in the ramp position, the ramp 3 is lowered andsubstantially aligned with the flipover 2. In the retention position,the ramp 3 is raised and substantially transverse (i.e., perpendicular)to the flipover 2. In the stowed position, the ramp 3 is folded over andagainst the flipover 2.

FIG. 2B illustrates the lift platform 100 in the lowered position andthe ramp 3 maintained in the stowed position, in accordance with anembodiment of the invention. In one embodiment, the lift platform 100rests against a ground level 200 when the lift platform 100 is in thelowered position for placing loads thereon. The platform section 1 andthe flipover 2 are unfolded and in substantial horizontal alignment withthe ground level 200. When the lift platform 100 is in the loweredposition, the ramp 3 may be maintained in the ramp position to functionas a ramp, in the retention position to prevent objects from rolling offthe edge of the flipover 2, or in the stowed position, as shown in FIG.2B. The ramp 3 is folded over and against the flipover 2 when the ramp 3is maintained in the stowed position, as shown in FIG. 2B.

FIG. 2C illustrates the lift platform 100 in the lowered position andthe ramp 3 maintained in the retention position, in accordance with anembodiment of the invention. The ramp 3 is raised and substantiallytransverse (i.e., perpendicular) to the flipover 2 when the ramp 3 ismaintained in the retention position, as shown in FIG. 2C. In theretention position, the ramp 3 prevents loads (e.g., wheeled carts) fromrolling off the lift platform 100.

FIG. 2D illustrates the lift platform 100 in the lowered position andthe ramp 3 maintained in the ramp position, in accordance with anembodiment of the invention. The ramp 3 is lowered and substantiallyaligned with the flipover 2 when the ramp 3 is maintained in the rampposition, as shown in FIG. 2D. In the ramp position, load (e.g., wheeledcarts) may be more easily rolled onto, or rolled off, the lift platform100. The ramp 3 comprises a bottom side 3C (FIG. 2B) and a top side 3D.

FIG. 3 illustrates an embodiment of a locking assembly 30, in accordancewith an embodiment of the invention. The locking assembly 30 furthercomprises a hinge arm member (“hinge member”) 11 coupled to the top side3D of the ramp 3 using at least one fastener 8 (FIG. 13A). The hingemember 11 includes a channel (i.e., cavity) 30C.

The locking assembly 30 further comprises a locking mechanism 20 formaintaining the pivoting ramp 3 in a selected position (e.g., a rampposition, a retention position, or a stowed position) when the lockingassembly 30 is locked. The locking mechanism 20 is disposed within thechannel 30C of the hinge member 11. In one embodiment, the lockingmechanism 20 comprises an elongated locking arm member (“locking arm”)5, a spring coil 30S (FIG. 6B), and a pivot axle 30L disposed on theopposing walls of the channel 30C.

A cam member/portion (“cam”) 6 is fixedly attached to the flipover 2,such that the hinge member 11 (and the attached ramp 3) is rotatable onpivot member 12 relative to the cam 6 (and the flipover 2) when thelocking assembly 30 is unlocked.

The elongated locking arm 5 has a first end 18 and a second end 19 thatis distal from the first end 18. In relation to the cam 6, the first end18 and the second end 19 of the locking arm 5 are the proximal end 18and the distal end 19 of the locking arm 5, respectively.

The cam 6 includes different portions or locking engagement surfaces forengaging with the first end 18 of the locking arm 5 to lock the lockingassembly 30 and maintain the ramp 3 in a selected position. The lockingarm 5 is pivotably mounted on the pivot axle 30L, such that the lockingarm 5 pivots on the axle 30L in relation to the channel 30C of the hingemember 11. The spring coil 30S is a torsion spring, which is disposedconcentric with the pivot axle 30L, with one end engaging the lockingarm 5 and another end engaging a portion of the channel 30C. The springcoil 30S is normally in torsion and pivots the locking arm 5 on the axle30L to move the proximal end 18 of the locking arm 5 downwardly into thechannel 30C and urged onto the cam 6. As such, the spring 30S alwaysexerts a biasing force on the locking arm 5 such that the first end 18of the locking arm 5 is spring-loaded on the cam 6.

The ramp 3 is maintained in a selected position when the locking arm 5engages with an engagement surface of the cam 6 to lock the lockingassembly 30. For example, the ramp 3 is maintained in the stowedposition when the proximal end 18 of the locking arm 5 engages a firstrecess portion (“first recess”) 14 (FIG. 13B) of the cam 6, as shown inFIG. 3. The proximal end 18 is in direct contact (i.e., flush) withengagement surface 6A of the first recess 14 of the cam 6 when the ramp3 is maintained in the stowed position. This prevents rotation of thehinge member 11 and the attached ramp 3 on the pivot member 12 away fromthe flipover 2, thereby maintaining the ramp 3 in the stowed position.

To release (i.e., unlock) the ramp 3 from a selected position, a force Fis applied to the distal end 19 of the locking arm 5 to overcome thebiasing torsion of the spring 30S and push the distal end 19 downwardinto the channel 30C of the hinge member 11. As the distal end 19rotates inside the channel 30C in direction X (e.g., clockwise in FIG.3), the proximal end 18 of the locking arm 5 disengages from the firstrecess 14 of the cam 6 and rotates away from the cam 6 in direction Y(e.g., clockwise in FIG. 3).

Generally, when the proximal end 18 of the locking arm 5 is disengagedfrom the cam 6, this unlocks the locking assembly 30 and the ramp 3 isfree to rotate relative to the flipover 2 on the pivot member 12 whilethe force F is maintained on the locking arm 5 to maintain the proximalend 18 of the locking arm 5 disengaged from the cam 6. For example, anoperator can rotate the ramp 3 relative to the flipover 2.

FIG. 4A shows a perspective view of the lift gate 10, wherein the liftplatform 100 is in folded and stowed position between the columns 51,and the ramp 3 is maintained in the stowed position relative to theflipover 2 by the locking arm 5, in accordance with an embodiment of theinvention. As noted, the lifting mechanism 52 comprises a parallel pairof vertically extending standards, posts or columns 51, each having avertically disposed actuator 4 (FIG. 2B) for vertically raising andlowering the lift platform 100 between ground level 200 and the vehiclebed 50. The linkages 53 (e.g., chains) maintain the lift platform 100 ina horizontal plane through the lifting range of the platform 100. Thelifting mechanism 52 may also rotate the lift platform 100 into a stowedposition, as shown in FIG. 4A. In the stowed position, the lift platform100 is fully folded, inverted, and vertically disposed between thecolumns 51.

FIG. 4B illustrates a cross-sectional view of the lift platform 100 inFIG. 4A about an axis A-A (FIG. 4A), in accordance with an embodiment ofthe invention. As shown in FIGS. 4A-4B, the flipover 2 is folded againstthe platform section 1 of the folded lift platform 100, and the ramp 3is maintained by the locking arm 5 of the locking assembly 30 in thestowed position (i.e., folded against the flipover 2). The proximal end18 of the locking arm 5 is in direct contact (i.e., flush) with recess14 of the cam 6 to maintain (i.e., lock) the ramp 3 in the stowedposition.

Repeatedly engaging the locking arm 5 with the cam 6 to maintain theramp 3 in a selected position may cause wear and tear to the proximalend 18 of the locking arm 5 and/or the cam 6. Further, repeatedlydisengaging the locking arm 5 from the cam 6 to release the ramp 3 froma selected position may also cause wear and tear to the proximal end 18of the locking arm 5 and/or the cam 6.

As a result of such wear and tear to the locking assembly 30, over timethe locking arm 5 may not properly engage the cam 6 to properly maintainthe ramp 3 in a selected position. FIG. 5A illustrates a perspectiveview of the lift platform 100 in the stowed position after the lift gate10 (FIG. 1) has been used for a period of time, causing wear and tear onthe locking arm 5 and/or the locking engagement surfaces of the cam 6.FIG. 5B illustrates a side view of the lift platform 100 in FIG. 5A,wherein the ramp 3 is not properly maintained in the stowed positionagainst the flipover 2 due to wear and tear on the locking arm 5 and/orthe cam 6.

FIG. 5C illustrates a cross-sectional view of the lift platform 100 inFIG. 5A about an axis A-A (FIG. 5A), wherein wear and tear wear on thelocking arm 5 and/or the cam 6 resulted in a gap G between the proximalend 18 of the locking arm 5 and the locking engagement surface 6A of thecam 6. The gap G prevents the proximal end 18 of the locking arm 5 fromproperly engaging with the first recess 14 of the cam 6 to maintain theramp 3 properly stowed against the flipover 2. As a result, the ramp 3may jut out relative to the flipover 2 even when the ramp 3 ismaintained in the stowed position, as shown in FIGS. 5A-5C. This isdistinguishable from FIGS. 4A-4B where the ramp 3 is properly foldedflat against the flipover 2 when the ramp 3 is maintained in the stowedposition. The gap G may be minimized or closed by replacing the worn outlocking arm 5 or the worn out cam 6 with a new locking arm 5 or a newcam 6, respectively.

According to another embodiment of the invention shown in FIG. 6A, alocking assembly 31 includes an adjustable locking arm 7A that allowsreducing such a gap G as necessary. The locking assembly 31 is similarto the locking assembly 30, except that the adjustable locking arm 7A isused in the locking assembly 31 instead of the locking arm 5 of thelocking assembly 30. The adjustable locking arm 7A has a first end 7AAand a second end 7AB that is opposite of the first end 7AA. In relationto the cam 6, the first end 7AA and the second end 7AB of the adjustablelocking arm 7A are the distal end 7AA and the proximal end 7AB of theadjustable locking arm 7A, respectively. The cam 6 is fixedly attachedto the flipover 2, such that the hinge member 11 (and the attached ramp3) is rotatable on pivot member 12 relative to the cam 6 (and theflipover 2) when the locking assembly 31 is unlocked.

In one embodiment, the elongated adjustable locking arm 7A includes anadjusting mechanism for adjusting the length of the adjustable lockingarm 7A. The adjusting mechanism allows selectively adjusting the lengthof the arm 7A between the axle 30L and the cam 6. In one implementation,the adjusting mechanism comprises an adjustable screw member 7B, aportion of which is threadably driven inside the adjustable locking arm7A at the proximal end 7AB of the adjustable locking arm 7A, allowingadjustments to the length of the adjustable locking arm 7A. Anadjustment may be made by unscrewing the screw 7B to lengthen the arm7A, or further screwing in the screw 7B to shorten the length of the arm7A.

The cam 6 includes locking engagement surfaces for engaging theadjustable screw 7B of the adjustable locking arm 7A in differentpositions relative to the cam 6. The spring coil 30S exerts a biasingforce on the adjustable locking arm 7A such that the adjustable screw 7Band the proximal end 7AB of the adjustable locking arm 7A arespring-loaded towards the cam 6. As described in detail later herein,the ramp 3 is maintained in a selected position when the adjustablescrew 7B of the adjustable locking arm 7A engages an engagement surface(i.e., a locking surface) of the cam 6.

FIG. 6B illustrates the locking assembly 31, wherein the ramp 3 ismaintained in the stowed position against the flipover 2, in accordancewith an embodiment of the invention. As shown in FIG. 6B, the adjustablescrew 7B engages engagement surface 6A of the first recess 14 of the cam6 to maintain the ramp 3 in the stowed position. A first end 30SA of thetorsion spring coil 30S is fixedly attached to a protrusion 11A of thehinge member 11. A second end 30SB of the torsion spring coil 30S isfixedly attached to a recess 7R (FIG. 7I) of the adjustable locking arm7A. In this manner, the proximal end 7AB of the arm 7A is spring-loadedagainst the cam 6. The spring coil 30S governs the rotational range ofthe adjustable locking arm 7A, as described above in relation of thelocking assembly 30.

FIGS. 7A-7I illustrate different views of the adjustable locking arm 7Aof the locking assembly 31, in accordance with an embodiment of theinvention. Specifically, FIG. 7A illustrates a perspective view of theadjustable locking arm 7A, apart from the hinge member 11. FIG. 7Billustrates a top view of the adjustable locking arm 7A. FIG. 7Cillustrates a cross-sectional view of the adjustable locking arm 7A.FIG. 7D illustrates a back view of the adjustable locking arm 7A. FIG.7E illustrates a side view of the adjustable locking arm 7A. FIG. 7Fillustrates a front view of the adjustable locking arm 7A. FIG. 7Gillustrates a front perspective view of the adjustable locking arm 7A.FIG. 7H illustrates a back perspective view of the adjustable lockingarm 7A. FIG. 7I illustrates an exploded view of the adjustable lockingarm 7A.

The proximal end 7AB of the arm 7A includes a threaded cavity 7AH forthreadably receiving the adjustable screw 7B. The adjustable screw 7Bhas a threaded body 16 (FIG. 7B) and a head 17. A portion of the body 16is threadably driven (i.e., screwed) inside the cavity 7AH of theadjustable locking arm 7A. In one embodiment, a securing nut 7C and awasher 7D further secure the adjustable screw 7B to the adjustablelocking arm 7A. The securing nut 7C may be loosened to adjust theadjustable screw 7B. For example, the securing nut 7C may be loosened toscrew the body 16 of the adjustable screw 7B further inside the cavity7AH of the adjustable locking arm 7A (i.e., shorten the arm 7A). Thesecuring nut 7C may also be loosened to unscrew the body 16 of theadjustable screw 7B out of the cavity 7AH of the adjustable locking arm7A (i.e., lengthen the arm 7A).

An aperture 7P extends axially through the adjustable locking arm 7A.The aperture 7P is shaped for receiving a bearing 7E, wherein thebearing 7E receives the pivot axle (pin) 30L for assembling the arm 7Aon the hinge member 11. The adjustable locking arm 7A is mounted on thepivot axle 30L (FIG. 6A) by inserting the pivot axle 30L through thebearing 7E.

The locking arm 7A further includes a recess 7R. As noted, the secondend 30SB of the torsion spring coil 30S is fixedly attached to therecess 7R.

FIG. 8A illustrates a top perspective view of the ramp 3 and the lockingmechanism 31, wherein the ramp 3 is maintained in the stowed position,in accordance with an embodiment of the invention. As noted, the ramp 3is in the stowed position when the ramp 3 is folded over and against theflipover 2. The ramp 3 is maintained in the stowed position when theadjustable screw 7B of the arm 7A engages with the first recess 14 ofthe cam 6, as shown in FIG. 8A.

FIG. 8B illustrates a side view of the ramp 3 when the ramp 3 ismaintained in the stowed position by the locking mechanism 31, inaccordance with an embodiment of the invention. Specifically, the ramp 3is maintained in the stowed position when the head 17 of the adjustablescrew 7B engages with the engagement surface 6A of the first recess 14of the cam 6 to lock the locking mechanism 31. As shown in FIG. 8B, thehead 17 of the adjustable screw 7B is in direct contact (e.g., flush)with the engagement surface 6A of the cam 6. The length of the arm 7Ahas been adjusted using the screw 7B such that there is no gap (i.e., nospacing) between the head 17 of the adjustable screw 7B and theengagement surface 6A of the cam 6 when the ramp 3 is maintained in thestowed position by the locking mechanism 31. As a result, the ramp 3remains properly folded against the flipover 2.

The ramp 3 may be released (i.e., unlocked) from the stowed position byapplying, and maintaining, a force F to the distal end 7AA of theadjustable locking arm 7A to push the distal end 7AA inside the channel30C of the hinge member 11. The distal end 7AA rotates inside thechannel 30C in direction X (e.g., clockwise in FIG. 8B) until the screw7B is no longer in contact with the cam 6, allowing rotation of thehinge member 11 and the attached ramp 3. The distal end 7AA of the arm7A contacts a stop member 30L of the hinge member 11, such that the stopmember 30L limits the rotational range of the distal end 7AA.

FIG. 9 illustrates a top perspective view of the locking assembly 31when the locking arm 7A is unlocked such that the ramp 3 is releasedfrom the stowed position, in accordance with an embodiment of theinvention. As the distal end 7AA of the adjustable locking arm 7A ispushed inside the channel 30C of the hinge member 11, the head 17 of theadjustable screw 7B disengages from the engagement surface 6A of the cam6, and the adjustable screw 7B and the proximal end 7AB of theadjustable locking arm 7A rotate away from the cam 6 in direction Y(e.g., clockwise).

The ramp 3 is free to pivot relative to the flipover 2 when the lockingassembly 31 is unlocked. For example, the ramp 3 may be positioned inthe retention position by an operator rotating the ramp 3 in direction V(e.g., counter-clockwise) to a raised position, and ceasing the force Fon the locking arm 7A, whereby the torsion spring 30S causes the arm 7Ato pivot such that screw 7B engages locking engagement surface 6B of thecam 6, as shown by example in FIGS. 10, 11A and 11B.

Specifically, FIG. 10 illustrates a side perspective view of the lockingassembly 31 with the hinge member 11 (and the attached ramp 3) moved tothe retention position, in accordance with an embodiment of theinvention. The ramp 3 may be maintained in the retention position byremoving the pressure F applied to the distal end 7AA of the adjustablelocking arm 7A. When the pressure F is removed, the spring coil 30Sbiases the adjustable screw 7B and the proximal end 7AB of theadjustable locking arm 7A towards the cam member 6 in direction Z (e.g.,counter-clockwise in FIG. 10), whereby the screw 7B of the arm 7Aengages with engagement surface 6B of a second recess 24 of the cam 6 tomaintain the ramp 3 in the retention position.

FIG. 11A illustrates a side perspective view of the ramp 3 when the ramp3 is maintained in the retention position, in accordance with anembodiment of the invention. In the retention position, the ramp 3 issubstantially transverse to the flipover 2. The ramp 3 is maintained inthe retention position when the adjustable screw 7B engages the secondrecess 24 of the cam 6, as shown in FIG. 11B.

Specifically, FIG. 11B illustrates a side view of the ramp 3 when theramp 3 is maintained in the retention position, in accordance with anembodiment of the invention. Specifically, the hinge member 11supporting the ramp 3 is maintained in the retention position by thelocking assembly 31 when the head 17 of the adjustable screw 7B engageswith the engagement surface 6B of the second recess 24 of the cam 6. Asshown in FIG. 11B, the head 17 of the adjustable screw 7B of the arm 7Ais in direct contact (i.e., flush) with the engagement surface 6B of thecam 6. There is no gap (i.e., no spacing) between the head 17 of theadjustable screw 7B and the engagement surface 6B of the cam 6. In theretention position, the arm 7A maintains the hinge member 11 (and ramp3) in a transverse angle relative the flipover 2, such that the ramp 3cannot be rotated (e.g., to the ramp position) relative to the flipover2 without disengaging the proximal end 7AB of the arm 7A from the recess24.

The ramp 3 may be released from the retention position and rotated tothe ramp position or the stowed position by applying a force F to thedistal end 7AA of the adjustable locking arm 7A to push the distal end7AA inside the channel 30C and unlock the locking arm 7A. The arm 7Apivots on axle 30L, such that distal end 7AA of the arm 7A rotatesinside the channel 30C in direction X (e.g., clockwise) and the proximalend 7AB of the arm 7A rotates away and disengages from engagementsurface 6B of the recess 24, while the force F is applied, as shown inFIG. 12.

In another embodiment, the ramp 3 is released from the retentionposition and rotated to the stowed position by applying a force Ragainst the ramp 3 to rotate the ramp 3 to the stowed position relativeto the flipover 2. The applied force R creates stress/tension between anengagement surface (e.g., engagement surface 6D) of the cam 6 and theadjustable screw 7B of the locking arm 7A. The stress/tension createdovercomes the spring-loading biasing force of the spring 30S and rotatesthe distal end 7AA of the adjustable locking arm 7A inside the channel30C in direction X (e.g., clockwise in FIG. 13B). The adjustable screw7B and the proximal end 7AB of the adjustable locking arm 7A disengagefrom the recess 24 of the cam 6 as the distal end 7AA of the adjustablelocking arm 7A rotates inside the channel 30C.

FIG. 12 illustrates a side perspective view of the locking assembly 31with the locking arm 7A unlocked, allowing the hinge member 11 (and theattached ramp 3) to rotate from the retention position towards the rampposition, as may be desired by an operator. In another example, with thelocking arm 7A unlocked, the hinge member 11 (and the attached ramp 3)may also be rotated back toward the stowed position, as may be desiredby an operator.

As the distal end 7AA of the adjustable locking arm 7A rotates insidethe channel 30C of the hinge member 11, the head 17 of the adjustablescrew 7B disengages from the engagement surface 6B of the cam 6, and theadjustable screw 7B and the proximal end 7AB of the adjustable lockingarm 7A rotate away from the cam 6 in direction Y (e.g., clockwise inFIG. 12).

The hinge member 11 (and ramp 3) can pivot on pivot member 12 relativeto the flipover 2 when the locking arm 7A is unlocked. For example, theramp 3 may be positioned in the ramp position by rotating the ramp 3 indirection W to a lowered position. As another example, the ramp 3 may bepositioned in the stowed position by rotating the ramp 3 in a directionopposite of W, as noted above.

FIG. 13A illustrates a top perspective view of the ramp 3 in the rampposition and maintained in that position by the locking arm 7A, inaccordance with an embodiment of the invention. The ramp 3 issubstantially aligned with the flipover 2 when the ramp 3 is in the rampposition. The ramp 3 is maintained in the ramp position when the force Fis removed, allowing the spring 30S to pivot the locking arm 7A on axle30L, such that adjustable screw 7B may essentially engage withengagement surface 6C of the cam 6 (FIG. 13B).

FIG. 13B illustrates a side view of the ramp 3 maintained in the rampposition when the locking arm 7A is locked, in accordance with anembodiment of the invention. The adjustable screw 7B is positionedunderneath the cam 6 when the ramp 3 is rotated to the ramp position.When the pressure F is removed from the distal end 7AA of the adjustablelocking arm 7A, the spring coil 30S biases the adjustable screw 7B andthe proximal end 7AB of the adjustable locking arm 7A towards the cam 6to maintain the ramp 3 in the ramp position. In one embodiment, theadjustable screw 7B rests against engagement surface 6C of the cam 6, asshown in FIG. 13B.

In one embodiment, the ramp 3 is released from the ramp position byapplying a force F to the distal end 7AA of the adjustable locking arm7A to overcome the spring-loading biasing force of the spring 30S andpivot the arm 7A on the axle 30L, such that the distal end 7AA rotatesinside the channel 30C. As the distal end 7AA of the adjustable lockingarm 7A rotates inside the channel 30C in direction X (e.g., clockwise inFIG. 13B), the adjustable screw 7B and the proximal end 7AB of theadjustable locking arm 7A rotates away from the cam 6 in direction Y(e.g., clockwise in FIG. 13B).

The ramp 3 is free to rotate relative to the flipover 2 when the lockingarm 7A is unlocked from the cam 6. For example, the ramp 3 may be movedto the retention position or the stowed position by rotating the ramp 3in direction U relative to the flipover 2.

In another embodiment, the ramp 3 is released from the ramp position byapplying a force R against the ramp 3 to rotate the ramp 3 to theretention position or the stowed position. As the ramp 3 rotates indirection U to the retention position or the stowed position, theapplied force R creates stress/tension between the engagement surface 6Cof the cam 6 and the adjustable screw 7B of the locking arm 7A. Thestress/tension created overcomes the spring-loading biasing force of thespring 30S and rotates the distal end 7AA of the adjustable locking arm7A inside the channel 30C in direction X (e.g., clockwise in FIG. 13B).The adjustable screw 7B and the proximal end 7AB of the adjustablelocking arm 7A rotate away from the engagement surface 6C of the cam 6in direction Y (e.g., clockwise in FIG. 13B) as the distal end 7AA ofthe adjustable locking arm 7A rotates inside the channel 30C.

FIG. 14 illustrates a side view of the locking mechanism 20 of thelocking assembly 31 when the locking arm 7A engages engagement surface6A of the cam 6 to maintain the ramp 3 in the stowed position, inaccordance with an embodiment of the invention. Repeated engagement ofthe adjustable screw 7B and the adjustable locking arm 7A with the cam 6to maintain the ramp 3 in a selected position causes wear and tear tothe adjustable screw 7B of the adjustable locking arm 7A, or the cam 6.Further, repeatedly disengaging the adjustable screw 7B and theadjustable locking arm 7A from the cam 6 to release the ramp 3 from aselected position may also cause wear and tear to the adjustable screw7B, the adjustable locking arm 7A, or the cam 6.

As a result of wear and tear to the locking mechanism 20, a gap G maydevelop between the cam 6 and the adjustable screw 7B when theadjustable locking arm 7A is biased by the spring coil 30S to lock thearm 7A and maintain the ramp 3 in a selected position, such as thestowed position. FIG. 14 shows a gap G between the engagement surface 6Aof the cam 6 and the head 17 of the adjustable screw 7B when theadjustable locking arm 7A is biased by the spring coil 30S to lock thearm 7A and maintain the ramp 3 in the stowed position. The gap G may bedue to said wear and tear, or other reasons, such as needs to adjustingthe length of the locking arm 7A to maintain a proper engagement betweenthe arm 7A and the cam 6. The gap G prevents adjustable screw 7B fromproperly engaging with the engagement surface 6A of the cam 6. As aresult, the ramp 3 may jut out relative to the flipover 2 when the liftplatform 100 is in the stowed position, as shown in FIG. 5C.

According to embodiments of the invention, the gap G may be minimized orclosed by adjusting the adjustable screw 7B. Specifically, the securingnut 7C is loosened to allow the body 16 of the adjustable screw 7B to bepartially unscrewed from the cavity 7AH (FIG. 7I) of the adjustablelocking arm 7A. As the body 16 of the adjustable screw 7B is unscrewed,the head 17 of the adjustable screw 7B moves towards the cam 6 indirection K to minimize or close the gap G (essentially lengthening thearm 7A). The adjustable screw 7B is adjusted until the head 17 of theadjustable screw 7B is in direct contact with the cam 6, and the ramp 3is properly folded against the flipover 2 (as in FIGS. 4A-4B). Once thegap G is closed, the securing nut 7C is tightened to secure theadjustable screw 7B to the adjustable locking arm 7A. Closing the gap Greduces/eliminates the ramp 3 from jutting out relative to the flipover2 when the ramp 3 is maintained in the stowed position.

FIG. 15 illustrates a top perspective view of an example lockingassembly 31 and a hinge assembly 40 that pivotally couple the ramp 3 tothe flipover 2, in accordance with an embodiment of the invention. Inone embodiment, the first edge 3A of the ramp 3 is pivotally coupled tothe second edge 2B of the flipover 2 via a locking assembly 31 at oneend 3E and a hinge assembly 40 at opposing end 3F of the ramp 3 (thelocking assembly 31 and the hinge assembly 40 are disposed at oppositeends 3E of the first edge 3A). In this embodiment, the lift gate 10includes one locking assembly for the ramp 3.

The hinge assembly 40 comprises a hinge member 9 that is coupled to thetop side 3D of the ramp 3 using at least one fastener 8. The hingeassembly 40 further includes at least pivot member 12 that enables theramp 3 to pivot relative to the flipover 2.

FIG. 16 illustrates another embodiment of a lift gate including a pairof locking assemblies for the ramp 3, according to an embodiment of theinvention. FIG. 16 shows locking assemblies 31 that pivotally couple theramp 3 to the flipover 2, wherein the first edge 3A of the ramp 3 ispivotally coupled to the second edge 2B of the flipover 2 via a pair oflocking assemblies 31, wherein a locking assembly 31 is disposed at oneend 3E of the first edge 3A of the ramp 3, and another locking assembly31 is disposed at one end 3F of the second edge 3A of the ramp 3.

In another embodiment of the invention, an adjusting mechanism mayinclude at least one adjustable screw 7B is driven inside the cam 6instead. In yet another embodiment, the proximal end 7AB of theadjustable locking arm 7A includes a first adjustable screw 7B, and thecam 6 also has at least one adjustable screw 7B. Embodiments of theinvention are useful in different types of lift gate systems.

FIG. 17A illustrates a perspective view of the ramp 3 in a stowedposition 1700 relative to the lift platform section 2 such as aflipover, in accordance with an embodiment of the invention. FIG. 17Billustrates a perspective view of the ramp 3 in a retention position1702 relative to the flipover 2, in accordance with an embodiment of theinvention. FIG. 17C illustrates a perspective view of the ramp 3 in aramp position 1704 relative to the flipover 2, in accordance with anembodiment of the invention.

The lift platform is shown in an unfolded position, wherein the liftplatform may be attached to and/or substantially aligned with a vehiclebed when the lift platform 100 is in the raised position. The liftplatform may include at least one load-carrying surface including aplatform section 1, a foldable section (“flipover”) 2, and/or aretention ramp section (“ramp”) 3. The flipover 2 may include theplatform section 1 and the flipover 2.

The platform section 1 may have a first edge and a second edge that isopposite of the first edge. The flipover 2 may have a first edge 2A anda second edge 2B that is opposite of the first edge 2A. The first edge2A of the flipover 2 may be pivotally coupled to the second edge of theplatform section 1. The ramp 3 may have a first edge 3A and a secondedge 3B that is opposite of the first edge 3A. The first edge 3A of theramp 3 may be pivotally coupled to the second edge 2B of the flipover 2via at least one locking assembly 32. In one embodiment, the first edge3A of the ramp 3 may be pivotally coupled to the second edge 2B of theflipover 2 via the locking assembly 32 at one side and a hinge assembly41 at another side. The locking assembly 32 and the hinge assembly 41may be disposed at opposite ends (sides), respectively, of the firstedge 3A. In another embodiment, the first edge 3A of the ramp 3 may bepivotally coupled to the second edge 2B of the flipover 2 via a pair oflocking assemblies 32. Each locking assembly 32 may be disposed at anopposite end of the first edge 3A of the ramp 3.

The ramp 3 may be connected to a coupling member that comprises a hingemember 61 for rotatably coupling the ramp 3 to the flipover 2. Thecoupling member may further include a pivot member 62 such as an axlepin for rotatably disposing the hinge member 61 relative to the flipover2, thereby enabling the hinge member 61 (and the attached ramp 3) tofreely rotate relative to the flipover 2 when the locking assembly 32 isunlocked, as described herein.

The ramp 3 may have a first surface 80 and a second surface 82. Thefirst surface 80 may be disposed opposite from the second surface 82.The first surface 80 may be disposed distal from the lift platformsection 2 in the stowed position 1700. The second surface 82 may beproximate and/or in contact with the lift platform section 2 in thestowed position. The second surface 82 may be proximate the flipover 2in the stowed position 1700, as shown in FIG. 17A. The second surface 82may be aligned with a top surface of the flipover 2 and form anextension of the top surface of the flipover in the ramp position 1704,as shown in FIGS. 17A-17C. The locking assembly 32 and/or the hingeassembly 41 may be attached to the first surface 80 of the ramp 3 suchthat the second surface 82 of the ramp is unobstructed in the rampposition 1704.

A handle 84 may be attached to the ramp 3 via a handle attachment point86, such as a rivet, bolt, adhesive, or the like. In some embodiments,the handle attachment point 86 may be disposed on the second surface 82of the ramp 3. In other embodiments, the handle attachment point 86 maybe disposed proximate the second edge 3B of the ramp 3. The handle 84may be used to rotate the ramp 3 between the stowed position 1700, theretention position 1702, and/or the ramp position 1704. The handle 84may allow a user or operator to control a speed of rotation of the ramp3 between the stowed position 1700, the retention position 1702, and/orthe ramp position 1704. In some embodiments, the ramp 3 may be locked atthe stowed position 1700, the retention position 1702, and/or the rampposition 1704 to prevent movement of the ramp 3.

An angled bracket 88 may be disposed on the first surface 80 of the ramp3. The angled bracket 88 may be angled such that the angled bracket 88protrudes farther from the first surface of the ramp proximate thesecond edge 3B of ramp. The angled bracket 88 may contact the ground orother surface in the ramp position 1704. In some embodiments, the angledbracket 88 may provide support to the ramp 3, such as when objects arebeing loaded onto the lift platform via travel from the ground or othersurface, over the second surface 82 of the ramp 3, and onto the flipover2. In other embodiments, the angled bracket 88 may make the ramp 3sturdier. The angled bracket 88 may prevent the ramp 3 from potentiallybending when it is impacted, such as by a cart.

FIG. 18A illustrates a perspective close-up view of the ramp 3 in alocked stowed position 1800 relative to the flipover 2, in accordancewith an embodiment of the invention. The locking assembly 32 includes ahinge arm member (“hinge member”) 61 coupled to the first surface 80 ofthe ramp 3 using at least one fastener 1008, such as a bolt, screw,threadable fastener, adhesive, weld, or the like. The hinge member 61includes a channel 1030C.

The locking assembly 32 further includes a locking mechanism 1020 formaintaining the ramp 3 in a selected position (e.g., a ramp position asshown in FIG. 17C, a retention position as shown in FIG. 17B, or astowed position as shown in FIG. 17A) when the locking assembly 32 islocked. The locking mechanism 1020 may be disposed within the channel1030C of the hinge member 61. In one embodiment, the locking mechanism1020 may include an elongated locking arm member (“locking arm”) 1005, aresilient member 1030S such as a spring coil, and a pivot point 1030L,such as a pivot axle, disposed on the opposing walls of the channel1030C. The elongated locking arm 1005 may have a first end 1018 and asecond end 1019 that is distal from the first end 1018. In relation tothe cam 1006, the first end 1018 and the second end 1019 of the lockingarm 1005 may be the proximal end and the distal end of the locking arm1005, respectively.

A cam member/portion (“cam”) 1006 may be fixedly attached to theflipover 2, such that the hinge member 61 (and the attached ramp 3) maybe rotatable on pivot member 62 relative to the cam 1006 (and theflipover 2) when the locking assembly 32 is unlocked. The cam 1006 mayinclude different portions or locking engagement surfaces for engagingwith the first end 1018 of the locking arm 1005 to lock the lockingassembly 32 and maintain the ramp 3 in a selected position. The lockingarm 1005 may be pivotably mounted on the pivot axle 1030L, such that thelocking arm 1005 pivots on the axle 1030L in relation to the channel1030C of the hinge member 61. The resilient member 1030S may be atorsion spring, which may be disposed concentric with the pivot axle1030L, with one end engaging the locking arm 1005 and another endengaging a portion of the channel 1030C. In other embodiments, theresilient member 1030S may be any tension device that maintains and/orreturns the locking arm 1005 to a set position relative to the hingemember 61. The resilient member 1030S may normally be in torsion andpivot the locking arm 1005 on the axle 1030L to move the proximal end1018 of the locking arm 1005 downwardly into the channel 1030C and urgedonto the cam 1006. As such, the resilient member 1030S may always beexerting a biasing force on the locking arm 1005 such that the first end1018 of the locking arm 1005 may be spring-loaded on the cam 1006.

The ramp 3 may be maintained in a selected position when the locking arm1005 engages with an engagement surface of the cam 1006 to lock thelocking assembly 32. For example, the ramp 3 may be maintained in thestowed position when the proximal end 1018 of the locking arm 1005engages a first recess portion of the cam 1006. The proximal end 1018may be in direct contact (i.e., flush) with an engagement surface of thefirst recess of the cam 1006 when the ramp 3 is maintained in the stowedposition. This prevents rotation of the hinge member 61 and the attachedramp 3 on the pivot member 62 away from the flipover 2, therebymaintaining the ramp 3 in the stowed position.

FIG. 18B illustrates a perspective close-up view of the ramp in anunlocked stowed position 1802 relative to the flipover, in accordancewith an embodiment of the invention. To release (i.e., unlock) the ramp3 from a selected position, a force may be applied to the distal end1019 of the locking arm 1005 to overcome the biasing torsion of theresilient member 1030S, such as a spring coil, and push the distal end1019 downward into the channel 1030C of the hinge member 61. As thedistal end 1019 rotates inside the channel 1030C such that the distalend 1019 is moved toward the ramp 3, the proximal end 1018 of thelocking arm 5 disengages from the first recess of the cam 1006 androtates away from the cam 1006 such that the proximal end 1018 is movedaway from the ramp 3.

Generally, when the proximal end 1018 of the locking arm 1005 isdisengaged from the cam 1006, this unlocks the locking assembly 32 andthe ramp 3 is free to rotate relative to the flipover 2 on the pivotmember 62 while the force is maintained on the locking arm 1005 tomaintain the proximal end 1018 of the locking arm 1005 disengaged fromthe cam 1006. For example, a user or operator can rotate the ramp 3relative to the flipover 2.

FIG. 18C illustrates a perspective close-up view of the ramp 3 in alocked retention position 1804 relative to the flipover 2, in accordancewith an embodiment of the invention. The locking arm 1005 engages thecam 1006 to hold the ramp 3 in place.

FIG. 18D illustrates a perspective close-up view of the ramp 3 in anunlocked retention position 1806 relative to the flipover 2, inaccordance with an embodiment of the invention. The locking arm 1005 isdisengaged from the cam 1006 to allow the ramp 3 to be moved to thestowed position or the ramp position.

FIG. 18E illustrates a perspective close-up view of the ramp 3 in a rampposition 1808 relative to the flipover 2, in accordance with anembodiment of the invention. The locking arm 1005 may engage ordisengage the cam 1006 to hold the ramp 3 in place.

FIGS. 19A-19E illustrate perspective, front, back, top, bottom, rightside, and left side views, respectively, of a locking arm bracket 1005,in accordance with an embodiment of the invention. The proximal end 1018of the arm 1005 includes a threaded cavity for threadably receiving theadjustment mechanism 1007B, such as an adjustable screw. The adjustmentmechanism 1007B may have a threaded body and a head 1017. A portion ofthe body may be threadably driven (i.e., screwed) inside the cavity ofthe adjustable locking arm 1005. In one embodiment, a securing nut 1007Cmay further secure the adjustment mechanism 1007B to the adjustablelocking arm 1005. The securing nut 1007C may be loosened to adjust theadjustment mechanism 1007B. For example, the securing nut 1007C may beloosened to screw the body of the adjustment mechanism 1007B furtherinside the cavity of the adjustable locking arm 1005 (i.e., shorten thearm 1005). The securing nut 1007C may also be loosened to unscrew thebody of the adjustment mechanism 1007B out of the cavity of theadjustable locking arm 1005 (i.e., lengthen the arm 1005).

An aperture 1007P may extend axially through the adjustable locking arm1005. The aperture 1007P may be shaped for receiving a bearing. Thebearing may receive the pivot axle (pin) 1030L for assembling the arm1005 on the hinge member 61, as shown in FIG. 18A. The adjustablelocking arm 1005 may be mounted on the pivot axle 1030L by inserting thepivot axle 1030L through the bearing, as shown in FIG. 18A.

The locking arm 1005 may further include an angled portion 1022 on a topportion of the locking arm 1005. The locking arm 1005 may furtherinclude an angled portion 1024 on a bottom portion of the locking arm1005. The angled portions 1022, 1024 are such that the locking arm 1005does not protrude outside of the channel 1030C and/or above the hingemember 61 when the locking arm 1005 is in a locked position.

FIG. 20A illustrates a perspective view of the liftgate 10 in a stowedposition, in accordance with an embodiment of the invention. FIG. 20Billustrates a perspective view of the liftgate 10 in a partiallyunstowed position, in accordance with an embodiment of the invention.FIG. 20C illustrates a perspective view of the liftgate 10 in anunstowed position with the ramp 3 in a stowed position 1700 relative tothe flipover 2, in accordance with an embodiment of the invention. FIG.20D illustrates a perspective view of the liftgate 10 with the ramp 3 ina retention position 1702 relative to the flipover 2, in accordance withan embodiment of the invention. FIG. 20E illustrates a perspective viewof the liftgate 10 with the ramp 3 in a ramp position 1704 relative tothe flipover 2, in accordance with an embodiment of the invention.

The present invention has been described in considerable detail withreference to certain preferred versions thereof; however, other versionsare possible. Therefore, the spirit and scope of the appended claimsshould not be limited to the description of the preferred versionscontained herein.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims below are intended toinclude any structure, material, or act for performing the function incombination with other claimed elements as specifically claimed. Thedescription of the present invention has been presented for purposes ofillustration and description, but is not intended to be exhaustive orlimited to the invention in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the invention. Theembodiment was chosen and described in order to best explain theprinciples of the invention and the practical application, and to enableothers of ordinary skill in the art to understand the invention forvarious embodiments with various modifications as are suited to theparticular use contemplated.

What is claimed is:
 1. A locking assembly for a ramp of a lift gate, thelocking assembly comprising: an elongated adjustable locking arm,wherein the locking arm is pivotably disposed on a pivot point relativeto the ramp, the locking arm including an adjustment mechanism foradjusting a length of the locking arm disposed on a proximal end of thelocking arm for engaging a cam portion, wherein the length of thelocking arm can be increased or decreased by adjusting the adjustmentmechanism at the proximal end of the locking arm; and a resilient memberfor spring loading the locking arm, wherein a biasing tension in theresilient member urges the proximal end of the locking arm to pivotablyengage with the cam portion to maintain the ramp in a selected position.2. The locking assembly of claim 1, further comprising: at least onefastener for coupling the locking assembly to a first surface of theramp, wherein the first surface of the ramp is disposed opposite from asecond surface of the ramp, and wherein the second surface of the rampis unobstructed in a ramp position of the selected position.
 3. Thelocking assembly of claim 2, wherein the cam portion has multipleengagement surfaces for individually engaging with the locking arm, suchthat selective engagement of the locking arm with each engagementsurface of the cam portion maintains the ramp in the selected position.4. The locking assembly of claim 2, wherein the first surface of theramp is disposed distal from a lift platform section in a stowedposition of the selected position.
 5. The locking assembly of claim 4,further comprising: a coupling member for rotatably coupling the ramp tothe lift platform section of the lift gate, the coupling memberincluding a channel in which the locking arm is pivotably disposed on apivot axle along the length of the locking arm, such that the lockingarm can pivot about the pivot axle for selectively engaging the camportion.
 6. The locking assembly of claim 5, wherein: the locking arm ispivotably disposed on said pivot axle along the length of the lockingarm between the proximal end of the locking arm and a distal end of thelocking arm; and upon exerting a force on the distal end of the lockingarm to overcome the tension in the spring, the locking arm pivots todisengage the proximal end of the locking arm from the cam portion andallows the ramp to be rotated relative to the lift platform section. 7.The locking assembly of claim 6, wherein: when the proximal end of thelocking arm engages with a first engagement surface of the cam portion,the ramp is maintained in the stowed position by the locking arm, suchthat the ramp is folded against a section of the lift platform section.8. The locking assembly of claim 7, wherein: when the proximal end ofthe locking arm engages with a second engagement surface of the camportion, the ramp is maintained in a retention position by the lockingarm, such that the ramp is substantially transverse to the lift platformsection.
 9. The locking assembly of claim 8, wherein: when the proximalend of the locking arm engages with a third engagement surface of thecam portion, the ramp is maintained in a ramp position, such that theramp is substantially aligned with the lift platform section.
 10. Thelocking assembly of claim 6, wherein: upon exerting a force on thedistal end of the locking arm to overcome the tension in the spring, thelocking arm pivots to disengage the proximal end of the locking arm fromthe cam portion and allows the ramp to be rotated relative to the liftplatform section between the stowed position, a retention position, theramp position.
 11. The locking assembly of claim 10, wherein: the distalend of the locking arm rotates into the channel as the proximal end ofthe locking arm rotates away to disengage the cam portion due toexertion of the force on the distal end of the locking arm; uponremoving the force on the distal end of the locking arm, the resilientmember pivots the locking arm to rotate the proximal end into engagementwith the cam portion and maintain the ramp in the selected positionrelative to the lift platform section; and a bottom of the channellimits the rotational range of the distal end of the locking arm. 12.The locking assembly of claim 2, wherein: the adjustment mechanismfurther includes an adjustable screw threadably disposed on the proximalend of the locking arm for engaging the cam portion, wherein partiallyunscrewing or partially screwing the adjustable screw relative to theproximal end of the locking arm increases or decreases the length of thelocking arm.
 13. The locking assembly of claim 2, wherein: theadjustment mechanism is disposed on the proximal end of the locking arm,such that the adjustment mechanism allows selective adjustment of thelength of a portion of the locking arm between the pivot point and thecam portion.
 14. The locking assembly of claim 2, wherein: theadjustment mechanism allows adjusting the length of the locking arm toreduce a gap between the proximal end of the locking arm and anengagement surface of the cam portion.
 15. The locking assembly of claim2, wherein: when the proximal end of the locking arm engages with afirst engagement surface of the cam portion, the ramp is maintained in astowed position by the locking arm, such that the ramp is folded againsta section of the a lift platform section; and the adjustment mechanismallows adjusting the length of the locking arm for engaging the camportion to maintain the ramp fully folded against the lift platformsection in a stowed position of the ramp.
 16. A lift gate system,comprising: a lift platform section; a ramp, wherein the ramp isrotatably coupled to the lift platform section; and a locking assemblyfor maintaining the ramp in a selected position relative to the liftplatform section, wherein the locking assembly comprises: an elongatedadjustable locking arm, wherein the locking arm is pivotably disposed ona pivot point relative to the ramp, wherein the locking arm includes anadjustment mechanism for adjusting a length of the locking arm disposedon a proximal end of the locking arm for engaging a cam portion, whereinthe length of the locking arm can be increased or decreased by adjustingthe adjustment mechanism at the proximal end of the locking arm; and aresilient member for spring loading the locking arm, wherein a biasingtension in the spring urges the proximal end of the locking arm topivotably engage with the cam portion to maintain the ramp in a selectedposition; at least one fastener for coupling the locking assembly to afirst surface of the ramp, wherein the first surface of the ramp isdisposed opposite from a second surface of the ramp, and wherein thesecond surface of the ramp is unobstructed in a ramp position of theselected position.
 17. The lift gate system of claim 16, wherein the camportion has multiple engagement surfaces for individually engaging withthe locking arm, such that selective engagement of the locking arm witheach engagement surface of the cam portion maintains the ramp in theselected position.
 18. The lift gate system of claim 16, furthercomprising: a lifting mechanism for supporting and moving the liftplatform section.
 19. The lift gate system of claim 16, wherein: whenthe proximal end of the locking arm engages with a first engagementsurface of the cam portion, the ramp is maintained in a stowed positionby the locking arm, such that the ramp is folded against a section ofthe lift platform section; when the proximal end of the locking armengages with a second engagement surface of the cam portion, the ramp ismaintained in a retention position by the locking arm, such that theramp is substantially transverse to the lift platform section; and whenthe proximal end of the locking arm engages with a third engagementsurface of the cam portion, the ramp is maintained in a ramp position,such that the ramp is substantially aligned with the lift platformsection.
 20. A method, comprising: maintaining a ramp of a lift gate ina selected position by engaging an elongated adjustable locking arm witha cam portion, the locking arm including an adjustment mechanism foradjusting a length of the locking arm disposed on a proximal end of thelocking arm for engaging a cam portion of the ramp; and increasing ordecreasing the length of the locking arm by adjusting the adjustmentmechanism at the proximal end of the locking arm; wherein the lockingarm is spring loaded by a resilient member having a biasing tension thaturges the proximal end of the locking arm to pivotably engage with thecam portion to maintain the ramp in a selected position; wherein the camportion has multiple engagement surfaces for individually engaging withthe locking arm, such that selective engagement of the locking arm witheach engagement surface of the cam portion maintains the ramp in theselected position; and wherein the locking assembly is coupled to afirst surface of the ramp, wherein the first surface of the ramp isdisposed opposite from a second surface of the ramp, and wherein thesecond surface of the ramp is unobstructed in a ramp position of theselected position.